Pro-am pornography is sub-genre of amateur pornography that refers to professionally made porn that features amateur actors/actresses, often appearing for nude milfs the first time in a pornographic film. John Stagliano is considered to have started the gonzo pornography genre with his Buttman series of films. Tentacle rape or shokushu goukan is found in some horror or hentai titles, with tentacled creatures having sexual intercourse with female characters. Rape pornography features performers simulating rape. Pornography may be presented in a variety of media, including books, magazines, postcards, photographs, sculpture, drawing, painting, animation, sound recording, film, video, and video games. Some straight actors have started acting in gay porn only to be accused of being gay while others first step was to strictly do solo scenes. As of 2013, little analysis of this paraphilia has been reported in medical literature. These scenes may involve the female actor calling for the shot to be directed at some specific part of her body. Several hundred exclusively pegging films were produced, as well as twice as many bisexual and straight films with strap-on scenes. Common positions include lying on back or face down, sitting, squatting, gay fuck kneeling or standing. For example, in Australia it is rated Refused Classification . In human sexuality, a threesome is sexual activity that involves three people at the same time. Threesome can also refer to a love triangle, a three-way romantic gay hentai relationship. They further argue that setting a discrete line between safe and not-safe activities ideologically denies consenting adults the right to evaluate risks vs rewards for themselves; that some adults will be drawn to certain activities regardless of the risk; and that BDSM play—particularly higher-risk play or edgeplay—should be treated with the same regard as extreme sports, with both respect and the demand that practitioners educate themselves and practice the higher-risk activities to decrease risk.